In the owners manual is a discussion of how the design progressed from the. After many years of being out of stock, we finally have the f6 transformer kits available. The feds and states may decide that there will be more deaths from a destroyed economy than from opening the economy prematurely. Pass most recent designs doesnt mean that it should be discounted. With kefs ls50s the kef ls50 is a respected, class a, referencequality minimonitorbut it sounded strangely wrong with the first watt j2. Srajan of 6moons told me that it is very close to his sit1 and considering that the f6 goes to 50 watts at 4 ohm, all of them in pure class a and from a fast and simple circuit, i getting goosebumps already. But know i have a diy version of the sit 2 but mine is class a push pull using nos sony vjefts and produces 40 watts into 4ohm. The total harmonic distortion has been trimmed to 0. I owned the fw j2 before this one and i can say the f6 has greater bass authority, deeper slam over the j2 variant, plus it helps that it has a bit more power in the lower ohm. Quite a few people have asked me for a regular sort of amplifi er, you know the kind you plug like any other, with some voltage gain and a real damping factor. The first watt j2 and zu essence are both made in the united states. The initial setup of the amplifier is very straightforward. The transcript of my presentation there is available on the first watt website under articles f6 talk at burning amp festival 2012. I dont normally build class a amps in the summer because my apartment gets really warm, but this time is an exception.
I used the same antek transformer used in the production version this proved expensive by the time hmrc had taken their cut. By way of response, nelson agreed to send me a pair of amps starting with the j2, a 25wpc into 8ohms solid state amp that has a twostage circuit that operates in pure singleended class a mode, with signal jfet devices forming the input stage and power jfet devices for the output. Or as nelson put it on his forum at diyaudio, the irfp240 will sound better in the new topology because it is largely the same. Audio magic kukama dac, galibier seracriggle string theory armzyx 4d, ar xa modifiedortofon cadenza red. Actually, i originally put up an erroneous version of. Natural tones and rollicking rhythms drove me straight through to appalachia. J2, sit1, and f7 first watt amplifiers by nelson pass. For a singleended circuit like his two sit amps, triodetype transistors are preferable. In 2008, nelson pass submitted an article on its new f5 power amplifier design to audioxpress. The transcript of my presentation there is available on the first watt website under articles f6 talk at burning amp festival 2012, and contains numerous comments and details. Im in the market for a new amp for my ks, and im trying to decide between a first watt, a pass labs aleph, the red wine sig 30, or going tubey. Several months later, i received a note from nelson informing me that a first watt f7 was cruising its way from. From nelson pass we have seen many an iconic audio product, such as the threshold electronics, the stasis circuit that nakamichi commissioned, and of course the pass labs products. I feel that its important to support audioxpress, a magazine with which i have a 35 year history, and which also serves as a mainstay for the diy community.
First watt f6 class a amplifier for sale us audio mart. First watt f7 amplifier, first watt b1 preamplifier, liberty audio b2b1 phono stage, graham slee accession phono stage sources. The latters equivalent power rating had made it one the best choices for conventional speakers in the specialops stable of firstwatt. Nelson pass first watt introduces new f7 power amplifier a. The only difference is that i used a separate power supply filter board for each channel. Page 3 these are the lowest distortion big power transistors i have seen. This is the lowest distortion yet achieved by either a zen or first watt amplifier, descending to. I announced the f6 on the pass forum at diyaudio with a little teaser schematic of what i had in mind. Jun 19, 2016 here are a few pics of my recently completed f6 build. The simplified upshot of this exchange is of course what many have believed and practiced all along. Circuit description the f5 is a pushpull, classa power amplifier. Firstwatt is about narrow paths less traveled, not milking repetition in overgrazed fat meadows. Before turn on amp for the first time, connect dmm across r2 the 0. Partly because this summer in copenhagen has been much more class a amp friendly i.
I used it only sparingly as i had my system tri amped for a long time and had many amps in rotation, but recently gave in and am using a simple amp to power my speakers now. First watt m2 just a bit of background first in order to put the m2 into perspective. Even it is in usual place as the further do, you can edit the tape in your gadget. Purchased last year from sna scumbag with the intention of using it to drive a pair of lamhorns in an additional system that never eventuated. The f6 thru 8 have already been conceptualized as higherpower mono versions of the 3, 4 and 5 respectively. I love this amp but maybe havent been able to get the best out of it yet. The first watt series of amplifiers started as an exploration of uncommon circuit designs in a low wattage format, and has been an ongoing endeavor for two decades now. Place the amplifier in a wellventilated location, as it draws about 180 watts during operation and. Heres a quick guide on the build of the first watt f6 power amp incorporating the the same same case and power supply as i used in the aleph j videos. This diyaudio build guide is all about the first watt f5 class a power amplifier, one of the most popular amplifiers built in the diy world. It is based on the design of firstwatt f6, and i made some efforts in the. Throwing everything i had inhouse at the f6 left me with a new found respect for nelson pass. It might seem like 25 watts per channel is on the low side for a large and heavy amplifier, but keep in mind that this amp is easily capable of driving 2 ohm loads and.
We imagined that many people would love to build a diy version of the first watt m2 amplifier except that the m2 requires jfets which are painfully. First watt f5 operation and service manual pdf download. Juts find it right here by searching the soft file in colleague page. Auburn, ca, july 22, 2016 first watts new f7 power amplifier msrp. I thought this might be interesting to those that appreciate amplifiers of these wattage ranges when paired with high efficiency104db or more horn systems but using different design technology. Crayon audio cfa02, bakoon amp12r, goldmundjob 225, gato dia250, clones 25i on loan, aura note premier, auralic merak on loan loudspeakers. First watt model f5 operation and service manual so far, first watt has made a few different amplifi ers. The sit 2 is based on a silicon carbide sic power jfet known as a static induction transistor. I have been into this hobby since 14 am now 40 and have lived long term with 2 speaker brands fried and spendor and 3 electronics brands nad, acurus, and quicksilver. The psu and amp boards were bought from the diyaudio store.
This is a group of photos overviewing the basic steps necessary to build a diy firstwatt nelson pass f5 classa amplifier. So this is my second listening session on the first watt f6. Kuzma stabi reference and technics sl10 turntables. Up for sale is my first watt f6 in great condition. For a pushpull topology like the f6 or f5 before it, a pentodetype mosfet really might have the edge. The first watt f6 offers a fantastic option to anyone in the market to drive sensitive speakers in the 90dbs8ohms territory and even picks a compelling fight with speakers that are moderately difficult to drive. May 14, 2014 anyone ever built or listened to the diy first watt amps f5, f4, aleph as im considering this as an option for a power amp, seems like a lot of amp for the build cost and class a should work nicely with my speakers. Power on, nothing happened by measuring voltage across r2, 0. Please note we have f6 parts transformer kits now available which include a pair of these pcbs. I reached out to nelson pass of first watt this summer and asked the whats what with first watt. New first watt products will find their way to market this year, and to make way for them, i am announcing last call on several models the sit1, sit2, f6, b4, and b1.
Firstwatt f6 build 2channel home audio the klipsch. M2 without shielding edcor transformer, it wont be noisy barely can heard noise from speaker when press ear against it. Firstwatt f6 build 2channel home audio the klipsch audio. Lets discuss speaker and preamp pairings you have found to work the best and why.
Albedo audio aptica,soundkaos wave 40, boenicke audio w5se, german physiks hrs120, zu audio submission, elac 4pi plus. The kit for diyaudio is no for the faint of heart but it is workable. The first watt sit 3 amp is blowing my mind, its so good, but so different sounding than any other amp ive heard at home. I am looking at an aric audio transcend push pull, a first watt j2, f6 or sit3, or a primaluna diaglogue premium. Lately they have kindly printed projects that i had already posted on the web, but i decided that they deserve a. First watt f6 great condition solid state audiogon. You can enjoy this soft file pdf in any period you expect.
For sale is my fantastic first watt f6 this is a pilot run, no. Whitestix, i can relate to the f5, i built the f5 and the f5 turbo version from the kits that were sold on diy audio. The f5 has the lowest distortion yet achieved by either a zen or first watt amplifier, descending to 0. They all run hot and that is just the nature of the beast,but the sound. Each first watt piece is a unique design and is best in some particular way. This build utilizes the v3 circuit board and the kit of circuit board parts available from. My listening comparison of first watt f3 vs cary cad2a3i and cary cad2a3se amplifiers in my system. Pickup cash, bank deposit, paypal with any fee extra info. First watt f7 stereo power amplifier the absolute sound.
Associated equipment rogue audio 99 super magnum rogue audio stereo 100 power amplifier carver m4. Or if you desire more, you can admission upon your computer or laptop to acquire full screen leading for pass labs xono manual. Oh, and my daughter is getting married here at sea ranch this saturday so hoist one for me. Steve guttenberg cnet all of that came into focus as i spent time with the first watt f7 20 watt perchannel stereo power amplifier, designed by nelson pass. I am trying to think of how to describe what i am hearing. They look alike because they all use the same basic chassis and power transformer. It is unique in that it has no capacitors in the amplifier circuit. Audible illusions l3a and brown audio labs sp1b preamps. Artesania audio exotyeric for front end, rajasthani hardwood rack for amps powerline conditioning. Since both output mosfets are both n type devices, the transformer is being used as a phase inverter. The red wine would have been the easy choice if it had more than one input, because it would have eliminated the need for a preamp. Recently, first watt came out with their latest limited edition amp the f7. But nelson points to the distortion spectrum at 1 watt and 1khz, and the 10db ratio between the second and third harmonic as being contributing factors to the f7s musicality. Most of the states, except florida of course, seem to understand whats going on.
Unlike f6 s jensen jt123flpch which is 50% nickel alloy core, m2s edcor transformer core is m6 steel, therefore it needs proper shielding. If you need to change the operating ac voltage, contact first watt. The burning amp festival is a diy audio event thats been held in san francisco in october for the past few years. Does anyone love the first watt sit2 audiogon discussion. In the 1970s, his first venture, threshold, broke new ground in solidstate designs, and hes still advancing the stateoftheart. Nelson pass talks at burning amp festival 2012 first watt. It is a 25 watt per channel class a mosfet power amplifier. First watt sit1 monoblocks black matched set serial numbers 1652, 1653 awesome sound. It seems most audiophiles enter the hobby already well upward from the bottom steps of power by using either a receiver with at least 100wpc or separates at the same, or higher, specification. Diy audio projects forum diy firstwatt f5 amplifier. Below i have included three jpegs and pdf pictures of the zen amp. Before considering the f6, i would find out if you source the jensen jt123flpch transformers. The transcript of my presentation there is available on the first watt website under articles and contains numerous comments and details about the original design, some of which are repeated here. Claimed to deliver 25wpc into 8 ohms or wpc into 4 ohms, the j2 has a damping factor of 20 at 8 ohms.
Steve guttenberg cnet all of that came into focus as i spent time with the first watt f7 20wattperchannel stereo power amplifier, designed by nelson pass. Metrum onyx using coax from a singxer su1 wupgrades. Wolfx700 measurement of diy firstwatt f6 clone audio science. This is so tough, but i can understand now what these terms may mean when a professional tries to describe these things.
Apr, 2020 hi folks, this is a project that i started long ago that was interrupted by a home move. First watt is a nelson pass enterprise, and hes the founder and ceo of pass laboratories. The parts came back across my hands this year and with a lot of help from walter of sar labs here in winnipeg the diy firstwatt f5 amplifier is finally complete. The f6 is a very interesting amplifier, first designed in 2012 and presented in october at the burning amp festival in san francisco. However, for a first time build, i went with a low voltage tube called a 6gm8, so the circuit had to be simplified into whats know as an ssrp. As such the f6 struck me as the longawaited fully matured replacement for the discontinued f5. The new f7 has been created as an updated version of the earlier f5 amplifier. Although the same enclosure is used by other first watt models, it doesnt look like a cheap diy item.
The first watt f5 operation and service manual attached below shows the schematic of the amp. These f6 clone boards use the same circuit as the nelson pass diyaudio firstwatt f6 described in the diyaudio firstwatt f6 thread thread. Here are a few pics of my recently completed f6 build. I am thinking of getting his latest f6 upgrade from f5 which is a 30 watt pure class a amp based on jfet output devices. On the up side, it makes it easy for me to test ideas and compare different designs with the hardware being a fixed constant. The f5 is a stereo power amplifier from first watt, a side project of nelson pass of pass labs. This very special amplifier dazzled the audiophiliac cnet. The firstwatt f6 is a power amplifier from the brilliant mind of our technical, spiritual, and menu advisor, nelson pass. A circuit of great interest is called a mu follower and a 6sn7 or 6dj8 tube would be a preferred tube. Circuitry, design concepts and measurements are detailed on nelsons first watt website. The f6 is definitely one of my favorite first watt amps. The first watt and falcons played the livin bejesus out of this jaunty lament.
This pair of f 5 clone circuit boards use the same circuit as the nelson pass firstwatt f 5 model. Do not open the amplifier, and if you do anyway, dont operate it with the cover off. Conservatively rated 810 due to age 1 year old and some scuff on the speaker terminals. Using an input transformer, the f6 of course also borrowed from the earlier m2. I also own the production version of the f7 and its very nice as well. Diy pass labs first watt f5 amp impressions audiogon. Mirrored f6 pcbs 2 jensen jt123flpch transformers 2 q12 matched irfp240 mosfets 4 r1.